From The Collaborative International Dictionary of English v.0.48:
Senator \Sen"a*tor\, n. [OE. senatour, OF. senatour, F. s['e]nateur, fr. L. senator.] 1. A member of a senate. [1913 Webster]
The duke and senators of Venice greet you. --Shak. [1913 Webster]
Note: In the United States, each State sends two senators for a term of six years to the national Congress. [1913 Webster]
2. (O.Eng.Law) A member of the king's council; a king's councilor. --Burrill. [1913 Webster]